Aaron Ciechanover won the Nobel Prize in Chemistry in 2004, for discovery of ubiquitin-mediated protein degradation, the means by which the cells of most living things discard unnecessary proteins. Ciechanover conducted his research at the Fox Chase Cancer Center in the late 1970s and early 1980s, and he shared the Nobel honors with his collaborators, Avram Hershko and Irwin Rose. A physician and biochemist, Ciechanover said he was not only surprised to win the Nobel Prize, but doubly surprised that it was in the Chemistry category, instead of Medicine.